Abstract
In the food industry, particularly in the dairy industry, significant amounts of thermal energy are required on different temperature levels. The thermal demand is linked to the production schedule and varies during the day. Hence, solutions are required to avoid part load operation and high peak loads on the refrigeration system. The subject of this case study is a dairy in central Norway, where combined CO2 heat pumps/chillers are used to cover the main heating and cooling loads. This study focuses on improving the current operation of the CO2 system by implementing a CTES with a phase change material. A Modelica model was used as a tool to investigate the process integration and evaluate the impact of the CTES on peak load reduction and a secured supply of process cooling load. The results show that the CTES can successfully smooth the provision of cold process water cooling, as supply and demand are decoupled from each other and sufficient process cooling can be provided at the same time.